Getting only one IPv6 address

[Leone]

I use two independent routers on Rogers network. One router works correctly (I use opnsense, but I don't think the problem is related), however when I connect second router it messes up IPv6 network on the first one. I noticed that that second device is getting exact same IPv6 address. How is it even possible if they have different MACs and ipv4 is assigned correctly to each of them. Basically I can't use IPv6 on both devices but I really need that :(. Any help is appreciated. Note I am not sure when this started, but few weeks ago everything worked correctly.

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[Leone]

JFYI I have recommended settings for IPv6:

• Use IPv4 connectivity as parent interface: yes
• Request only a IPv6 prefix: no
• DHCPv6 Prefix Delegation Size: 64
• Send IPv6 prefix hint: yes

Surprisingly, I am also getting ipv6 assigned with any combinations of these options (but as I said it's only one ip address for both interfaces).

[-G-]

@Leone  When using the Ignite gateways in Bridge Mode, you can only have one external router/firewall device connected.  Yes, Rogers still allows you two public IPv4/IPv6 address allocations.  However, when the Ignite gateway is in Bridge Mode, it still has internal services running... so it takes one of the public IP address allocations, and that leaves only one remaining for your equipment.  If you have two devices connected, they will end up competing with one another for the only remaining IPv4/IPv6 address allocations available.

[Leone]

But I am getting 2 ip4 addresses. And before I am sure it was working fine with ip6 too.

[-G-]

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@Leone wrote:

But I am getting 2 ip4 addresses. And before I am sure it was working fine with ip6 too.

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You may be getting different IPv4 addresses but only two devices (of the three, including the gateway) will have working network connectivity at any given time, and the connectivity for all devices will be intermittent at best.

[-G- · Accepted solution]

@Leone If you don't believe what I am telling you, try disconnecting all of your devices for 10 minutes.  Next connect only your OPNsense box and confirm that your network connectivity is stable.  Next unplug everything for another 10 minutes and test your router's connectivity.  Lastly, try reconnecting your OPNsense box (with your router also still active) and I'm quite certain that you will start to see things breaking again.